Vibration isolation systems, considered as systems with single degree of freedom

Mohammed Zebilila,Jury Chernov,S Jemioło,M Krzemiński,M Mitew-Czajewska,M Gajewski,A Zbiciak

doi:10.1051/matecconf/201711700181

Mohammed Zebilila, Jury Chernov + Show 5 more

Open Access

https://doi.org/10.1051/matecconf/201711700181

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Abstract

The research considers and analyzes vibration isolation systems, whose design schemes are single degree of freedom systems, including nonlinear elements - displacement limiter and viscous damper. Presented are calculation formulas in closed form for linear systems in operational modes (for harmonic and impulse loads), algorithms and examples of calculation of linear and nonlinear systems in operational and transient modes. The calculation method and the above dependences are written using the transfer (TF) and impulse response functions (IRF) of linear dynamical systems and dependencies that determine the relationship between these functions. The effectiveness of 2 options of vibration isolation systems in transient modes is analyzed. There is significant reduction of load from the equipment to the supporting structures in the starting-stopping modes by the use of displacement limiter.

Highlights

Vibration-active equipment stationed close to buildings or installed on structures cause such structures to undergo oscillation, which often go above the limits set in building standards and design manuals [1]
The changing of the structural stiffness is done by switching devices which are controlled by control laws [10,11,12]
The calculation schemes of single degree of system with displacement limiter and viscous damper are shown in figure 1

Summary

Introduction

Vibration-active equipment stationed close to buildings or installed on structures cause such structures to undergo oscillation, which often go above the limits set in building standards and design manuals [1]. In order to reduce vibrations in transient modes in many fields of technology, including the operation of vibration isolated equipment, systems with non-linear elements - displacement limiters and viscous dampers are widely used. In a significant part of the design process, dampers are constantly associated with an oscillating body Such dampers, including a stator and a rotor, are tuned to the frequency of oscillations of the object and are effective in damping vibrations in transient modes. The standby stiffness and the structure disengage separately These types of vibration isolation could be employed in reducing the levels of oscillation of equipment with rotating parts (Fans, compressors) and on screen machines in transition modes - starting and stopping modes[16]

Algorithm of calculation

Numerical example

Results and discussion

Conclusion